Well tool with expansible anchor and friction drag



Sept. 16, 1969 J. H. CURRENT 3,467,186

WELL TOOL WITH EXPANSIBLE] ANCHOR AND FRICTICN DRAG Filed Aug. 15. 19672 Sheets-Sheet l (f /r7 es fr- (aw/e0 f INVENTOR.

Al'fd/PNE Y Sept. 16, 1969 J. H. CURRENT 3,467,186

WELL TOOL WITH EXPANSIBLE ANCHOR AND FRICTION DRAG Filed Aug. 15. 1967 2Sheets-Sheet 2 l 92 a! I 6,6 -92 a! (fame; fr. or/e42 INVENTOR. w 7

United States Patent Int. Cl. E21b 33/129, 23/06 US. Cl. 166-216 4Claims ABSTRACT OF THE DISCLOSURE A unitary slip and drag blockstructure including a tubular member having longitudinally spaced slipand drag portions, said member having slots extending longitudinally forless than the full length of said member to divide said slip and dragportions into a plurality of interconnected segments which areexpansible and contractible jointly as well as independently on eachother.

This is a division of application Ser. No. 500,946, filed Oct. 22, 1965.

This invention relates to a well tool and, more particularly, to apacker apparatus for use in a well bore.

In the drilling and production of oil wells, it is often necessary toisolate zones or formation in the well bore in order to produce from andto permit or prevent the treating of such selected zones. The isolationof such zones or formations is commonly done by use of packers or bridgeplugs. The present invention is primarily concerned with a tubing-typeretrieval packer for use in a cased well bore. Such packers normallyinclude a slip and drag block assembly in combination with a packerelement. The packer is set by first unlocking a jaying mechanism andthen applying tension or compression to the running in tubing whichsequentially sets the slips into the well casing and expands the packerelement. The expanded packer element seals off an annulus between thecasing and the body of the packer. At some later time, the packer may beretrieved by manipulating the tubing to sequentially contract the packerelement and unlock the slips from the casing. The packer is then lockedin an inactive position by the jaying mechanism and retrieved to thesurface.

In the event the packer should become stuck, a shearing device isusually provided between the packer body and the assembly holding thepacker element. By applying greater than normal forces to the tubingstring, the stuck parts can be made to shear from the body so that thebody portion of the packer may be retrieved. The remainder of the toolis then fished or drilled out.

In the construction of such packers, it is important to maintain theapparatus as simple as possible for the reason that the more complicatedthe mechanism may be, the more likelihood there is that the mechanismwill malfunction and prevent the retrieval of the packer by normalmeans.

It has been found that springs used for operating the slips and dragblocks are particularly susceptible to corrosive action of well fluidsand often fail to operate. The failure of the springs to operate maycause the packer to become stuck in the well. Non-corrosive springs onthe other hand are expensive and further add to the cost of the packer.In a typical packer, the slip and drag block assembly may be comprisedof six slips, six slip pins, six drag blocks and eighteen springs; eachbeing separate parts. Cost and su ceptibility to malfunction arenormally proportional to the number of individual parts comprising theassemblies. Where such packers are left in the well 3,467,186 PatentedSept. 16, 1969 bore for use over extended periods of time, the cost ofmanufacture of the packer becomes even more important. It is, therefore,an object of the present invention to provide a new and improved packerwhich is economical to construct and simple in it operation.

With this and other objects in view, the present invention relates to apacker having a resilient element expandable by virtue of relativemovement between upper and lower gauge rings. An expander coneassociated with one of the gauge rings actuates slips to provide a rigidstop for that gauge ring against which movement of the other gauge ringcompresses the resilient element and thereby laterally expands theelement into engagement with the well. Slip and drag block means areconstructed as a single unit. The drag block means permits a jayingmechanism to be operated, which, in turn, provides for relative movementbetween the slips and expander cone. Shear means are provided betweenone of the gauge rings maintaining the packer element expanded and thepacker mandrel so that should the apparatus become stuck in the wellbore, the shear ring may be sheared to let the packer element collapseand permit removal of the tool from the well. The shear ring is soconstructed as to permit a convenient selection of shearing forces.

A complete understanding of this invention may be had by reference tothe following detailed description when read in conjunction with theaccompanying drawings illustrating an embodiment thereof, wherein:

FIG. 1 shows a partial sectional view of a packer embodying features ofthe present invention;

FIG. 2 shows a partial sectional view of a packer utilizing analternative slip and drag block arrangement;

FIG. 3 shows a sectional view of part of a packer, illustrating ashearing mechanism;

FIG. 4 is a sectional view taken along lines 66 of FIG. 3; and

FIG. 5 is a side view of the shearing device shown in FIGS. 3 and 4.

Referring to FIG. 1, the packer apparatus is comprised of a mandrel orbody 12 which is threaded at its upper end'for connection to a string oftubing. An elastomer packer 14 element is positioned about the body andis supported on one end by an upper gauge ring 1 6 which, in tum, isconnected to the mandrel by a shear pin or shear ring 18. The other endof the packer element is supported by a combination gauge ring andexpander 20. The gauge ring and expander 20 is supported on the mandrelby means of an annular shoulder 22 extending outwardly from the mandrel.

A unitary member 24 is arranged about the packer mandrel below theexpander. This unitary member has portions thereon serving as slips anddrag blocks. The member is preferably machined or otherwise formed of asingle piece of material. An upper portion 26 of this unitary member hasteeth 28 formed therein to render the upper portion operable as slips.The upper end of the slip portion 26 has an inwardly sloping surface 30thereon which mates with an outwardly sloping surface 32 formed on theexpander 20. These sloping surfaces are arranged so that relativemovement of the slip and expander toward one another will cause the slipto cam outwardly into engagement with the well casing. An enlargedportion 34 at the other end of the unitary member forms a drag blockmeans for frictionally engaging the interior of the well casing. Aplurality of longitudinal slots 36 are formed through the unitary memberwith adjacent slots running from alternate ends of the member to aterminal point 38 near the opposite end. The terminal point is in theshape of a hole through the member which serves as a stress reliefmeans. This arrangement of slots in the unitary member permits themember to be compressed and thus reduced in size or diameter upon theapplication of radial forces inwardly against the member. A space 40 isprovided between the unitary member and the mandrel to permit suchradial compression. The lower end of the unitary member is supported bya drag block cage 42 having a hook-shaped annular lug 44 extendingupwardly therefrom. The hook portion 46 on the lug is received within arecess 48 at the lower end of the unitary member. An inwardly extendingJ pin 50 which is attached to the drag block cage 42 is slidablyreceived within a conventional J-slot 52 normally used with such packerdevices.

In the operation of the apparatus shown in FIG. 1, the packer is loweredinto the well bore to a depth where it is desired to expand the packeragainst the wall of the well. At this point, the packer mandrel israised upwardly and rotated to place the J-pin 50 into a longlongitudinal section of the J-slot 52. The mandrel is then lowered withthe pin 50 riding upwardly in the long section of the J-slot. The J-pin50 is held from downward movement with the mandrel by frictionalengagement of the drag block 34 against the wall of the well. Relativemovement between the mandrel and unitary member, on which the drag blockis formed, causes the sloping portion 30 of the slip to ride upwardly onthe surface 62 of the expander thereby caming the slips outwardly intogripping engagement with the well bore. Further downward movement of themandrel pushes the upper gauge ring, packer element, and lower gaugering expander against the now-anchored slips and compresses theelastomer packing element between the upper and lower gauge rings. Suchcompression of the ends of the packer element causes the element toexpand radially outwardly into sealing engagement with the wall of thewell.

When it is desired to unset the packer, weight is picked up off themandrel 12 by lifting on the tubing string. This permits the packerelement to contract and lets the expander cone slide upwardly frombehind the slip thereby permitting the slip to disengage from the wallof the well. The teeth 48 on the slips are slanted downwardly tofacilitate their disengagement from the wall of the well when pulledupwardly. Should the packer fail to unset, a larger than normal forcemay be applied upwardly on the mandrel which force is sufficient toshear the pin 18 connecting the upper gauge ring to the mandrel.Shearing of this pin releases the upper gauge ring to permitdecompression of the elastomer packing element thus releasing thesealing engagement.

The apparatus has thus far been described as being operated as acompression set packer. However, it is readily seen that by invertingthe apparatus on the tubing string, the packer may be set by applyingtension forces to the mandrel.

Referring now to FIG. 2 of the drawings, an alternative arrangement ofparts is shown which features a separate slip and drag block. The dragblock 54 is constructed from a unitary piece of material and has thesame slotted arrangement as shown with respect to the unitary member inFIG. 1. A drag block cage 56 is slidably received about the mandrel 12,the cage having overlapping flange members 58 which engage end tabs 59on the drag block to support the drag block on the packer. A I-pin 60which is connected to the cage 56 extends inwardly therefrom and ismovably received within J-slot 62 in the mandrel 12. A hook-shapedannular lug 64 extends upwardly from the cage and is received in acomplementary recess 66 on a slip member 68. One end of slip member 68has a sloping portion 70 thereon which cooperates with oppositelysloping portion 72 on the expander cone 74 positioned below the packerelement 76.

In the operation of the apparatus shown in FIG. 2, the packer is runinto the well bore to a point at which it is desired to expand thepacker. The mandrel is raised upwardly and rotated to move the I-pin 60into an elongated portion of the I-slot 62 whereupon the mandrel islowered. Lowering of the mandrel at this point causes the expander cone74 to move downwardly beneath the slips 68. The slips are prevented frommoving downwardly due to the frictional engagement of the drag block 54against the well bore. This downward movement of the expander cone 74cams the slips 68 outwardly into gripping engagement with the well boreto anchor the slips therein. Continued downward movement compresses thepacker element between the upper and lower gauge rings and radiallyexpands the packer element 76 outwardly into sealing engagement with thewell bore. The packer of FIG. 2 is unset in a manner similar to that setforth with respect to the operation of the apparatus of FIG. 1.

FIGS. 3, 4 and 5 show a shearing means to be used with a well tool suchas the packer described herein. Referring to FIG. 3, the upper end of apacker mandrel 78 is shown attached to the lower end of a tubing 80. Apacker element 82 is shown positioned about the mandrel. An uppergaugering 84 is positioned over the end of the packer element. Anannular recess 86 is formed in the outer wall of the packer mandrel. Anarcuate shaped shear member 88 is positioned about the mandrel with theinner edge of the shear member fitted into the recess 86 on the mandrel.A plurality of openings in the shear member receive screws 90 forfastening the shear memher to the gauge ring 84. Radial slots or grooves92 (FIG. 4, 5 are formed part way through the shear member 88 so thatportions or segments of the shear member may be easily broken therefrom.Each of the portions between the recesses 92 in the shear member has anopening for receiving a screw or bolt 90 to fasten each segment of themember to the gauge ring 84.

With the arrangement of shearing means as set forth above, the amount ofshear means needed in a well tool may be determined and selected at thewell location. The tool is shipped to the well location with a maximumamount of arcuate segments or shear means which would be needed in anysituation. The operator then removes segments of the arcuate memberuntil the number of the segments remaining corresponds to the shearvalue he wishes to provide on the tool. Each of the segments rep resentsan equal amount of shear resistive material, for each segment mayrequire 10,000 pounds force to shear the segment. The grooves 92 in thearcuate shear member are sufficiently deep to permit the pieces to beeasily broken from the ring. As will be appreciated, the shear memberswould be placed about the mandrel in such a way as to balance ordistribute the shearing forces applied about the mandrel.

Although the features of the invention herein have been described foruse with a packer, it is readily seen that such features would haveapplication to other well tools. Additionally, while particularembodiments of the present invention have been shown and described, itis apparent that changes and modifications may be made without departingfrom this invention in its broader as pects and, therefore, the aim inthe appended claims is to cover all such changes and modifications asfall within the true spirit and scope of this invention.

What is claimed is:

1. A tool adapted for use in a well comprising: an elongated body, aunitary annular sleeve on said body, said sleeve having a drag blockportion for frictionally engaging the wall of a well and a slip portionfor gripping the wall of a well, said drag block portion and slipportion being longitudinally spaced on said unitary annular sleeve by aconnecting portion having a relatively thin cross section, said sleevehaving a plurality of adjacent slots formed in the wall of said sleeve,said adjacent slots running from alternate ends of said sleeve to stressrelief means near the opposite end of said sleeve, expander means formoving said slip portion into gripping engagement with the well, andselectively operable means for effecting relative movement between saidexpander means and slip portion to operate said slip portion, saidconnecting portion of said unitary annular sleeve permitting radialmovement of said slip portion relative to said drag block portion.

2. A unitary slip and drag block structure for use in anchoring a welltool in a well bore, comprising an elongated generally tubular memberhaving a slip portion adjacent one end with teeth formed on its outerperiphery, said slip portion having inclined inner surfaces, said memberhaving a drag portion adjacent its other end with outer peripheralsurfaces adapted to frictionally engage a well conduit wall, said memberfurther having slots extending in longitudinal directions for less thanthe full length of said member to divide said slip and drag portionsinto a plurality of circumferentially spaced segments which are joinedto an adjacent segment at each end whereby said slip and drag portionsare jointly as well as independently expansible and contractible.

3. The structure of claim 2 wherein said member further has athin-Walled portion between said slip and drag portions.

4. A unitary slip and drag block structure for use in anchoring a welltool in a well bore, comprising: an elongated generally tubular memberhaving a first portion with teeth formed on its outer periphery, saidfirst portion having inclined inner surfaces, said member having asecond portion spaced from said first portion and having outerperipheral surfaces adapted to frictionallysengage a well conduit wall,said member having slots extending in alternating longitudinaldirections from one end of said member to points adjacent the oppositeend thereof, and said member providing resilient portionsinterconnecting opposite ends of said segments with adjacent segments,so that said first and second portions are jointly as well asindependently expansible and contractible.

References Cited UNITED STATES PATENTS 1,123,197 12/1914 Kinney 166-2162,345,888 4/1944 Scott 166'216 3,018,830 1/1962 Springer 166-1383,303,885 2/1967 Kisling 166-135 3,318,385 5/1967 Conrad 166-122 JAMESA. LEPPINK, Primary Examiner

